'use strict'
const path = require('path')
const defaultSettings = require('./src/settings.js')
const CompressionPlugin = require('compression-webpack-plugin')

function resolve(dir) {
  return path.join(__dirname, dir)
}

const name = defaultSettings.title || 'vue Admin Template' // page title

// If your port is set to 80,
// use administrator privileges to execute the command line.
// For example, Mac: sudo npm run
// You can change the port by the following methods:
// port = 9528 npm run dev OR npm run dev --port = 9528
const port = process.env.port || process.env.npm_config_port || 8888 // dev port
// 忽略
let externals = {}
if (process.env.NODE_ENV === 'production') {
  externals = {
    // key: 包名
    // 去window查找
    echarts: 'echarts',
    'element-ui': 'ELEMENT',
    vue: 'Vue',
    xlsx: 'XLSX',
    'cos-js-sdk-v5': 'COS',
  }
}
// All configuration item explanations can be find in https://cli.vuejs.org/config/
module.exports = {
  /**
   * You will need to set publicPath if you plan to deploy your site under a sub path,
   * for example GitHub Pages. If you plan to deploy your site to https://foo.github.io/bar/,
   * then publicPath should be set to "/bar/".
   * In most cases please use '/' !!!
   * Detail: https://cli.vuejs.org/config/#publicpath
   */
  publicPath: './',
  outputDir: 'dist',
  assetsDir: 'static',
  lintOnSave: false,
  productionSourceMap: false,
  devServer: {
    port: port,
    open: true,
    overlay: {
      warnings: false,
      errors: true,
    },
    proxy: {
      // http://localhost:8888/api/login
      '/api': {
        target: 'http://ihrm.itheima.net/', // 跨域的服务器
      },
    },
  },
  // 都可以对webpack进行自定义配置
  configureWebpack: {
    // provide the app's title in webpack's name field, so that
    // it can be accessed in index.html to inject the correct title.
    name: name,
    resolve: {
      alias: {
        '@': resolve('src'),
      },
    },
    // 忽略打包
    externals,
  },
  // 通过链式语法自定义配置webpack
  chainWebpack(config) {
    // process.env.NODE_ENV: 获取环境变量
    // process.env.NODE_ENV === production 生产环境
    // if (process.env.NODE_ENV === 'production') {
    //   config.plugin('compressionPlugin').use(
    //     new CompressionPlugin({
    //       filename: '[path].gz[query]',
    //       algorithm: 'gzip',
    //       test: /\.(js|css)(\?.*)?$/i, // 用['js', 'css']有个缺点就是map文件也会压缩,这时候压缩就没多大意义,用正则会更好一点
    //       threshold: 10240, // 单位bytes, 大于10k才会考虑压缩
    //       minRatio: 0.8, // 默认压缩率, 压缩结果能低于百分之八十才会进行压缩
    //       // deleteOriginalAssets: true //是否删除源文件(不推荐删除, 容易出现chunk报错问题)
    //     })
    //   )
    // }
    // 给html-webpack-plugin插件传递参数
    config.plugin('html').tap((args) => {
      args[0].myEnv = process.env.NODE_ENV
      return args
    })
    // it can improve the speed of the first screen, it is recommended to turn on preload
    const imagesRule = config.module.rule('images')
    imagesRule
      .use('image-webpack-loader')
      .loader('image-webpack-loader')
      .options({
        bypassOnDebug: true,
      })
      .end()
    config.plugin('preload').tap(() => [
      {
        rel: 'preload',
        // to ignore runtime.js
        // https://github.com/vuejs/vue-cli/blob/dev/packages/@vue/cli-service/lib/config/app.js#L171
        fileBlacklist: [/\.map$/, /hot-update\.js$/, /runtime\..*\.js$/],
        include: 'initial',
      },
    ])

    // when there are many pages, it will cause too many meaningless requests
    config.plugins.delete('prefetch')

    // set svg-sprite-loader
    config.module.rule('svg').exclude.add(resolve('src/icons')).end()
    config.module
      .rule('icons')
      .test(/\.svg$/)
      .include.add(resolve('src/icons'))
      .end()
      .use('svg-sprite-loader')
      .loader('svg-sprite-loader')
      .options({
        symbolId: 'icon-[name]',
      })
      .end()

    config.when(process.env.NODE_ENV !== 'development', (config) => {
      config
        .plugin('ScriptExtHtmlWebpackPlugin')
        .after('html')
        .use('script-ext-html-webpack-plugin', [
          {
            // `runtime` must same as runtimeChunk name. default is `runtime`
            inline: /runtime\..*\.js$/,
          },
        ])
        .end()
      config.optimization.splitChunks({
        chunks: 'all',
        cacheGroups: {
          libs: {
            name: 'chunk-libs',
            test: /[\\/]node_modules[\\/]/,
            priority: 10,
            chunks: 'initial', // only package third parties that are initially dependent
          },
          elementUI: {
            name: 'chunk-elementUI', // split elementUI into a single package
            priority: 20, // the weight needs to be larger than libs and app or it will be packaged into libs or app
            test: /[\\/]node_modules[\\/]_?element-ui(.*)/, // in order to adapt to cnpm
          },
          commons: {
            name: 'chunk-commons',
            test: resolve('src/components'), // can customize your rules
            minChunks: 3, //  minimum common number
            priority: 5,
            reuseExistingChunk: true,
          },
        },
      })
      // https:// webpack.js.org/configuration/optimization/#optimizationruntimechunk
      config.optimization.runtimeChunk('single')
    })
  },
}
